<template>
  <div class="header">
    <router-link tag="div" to="/" class="header-abs" v-show="showAbs">
      <div class="iconfont header-abs-back">&#xe624;</div>
    </router-link>
    <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
      <router-link to="/">
        <div class="iconfont header-fixed-back">&#xe624;</div>
      </router-link>
      景点详情
    </div>
  </div>
</template>
<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      // console.log('scroll')
      const top = document.documentElement.scrollTop
      if (top > 0) {
        let opacity = top / 200
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = { opacity }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  // activated () {
  //   window.addEventListener('scroll', this.handleScroll)
  // },
  // deactivated () {
  //   window.removeEventListener('scroll', this.handleScroll)
  // },
  created () {
    window.addEventListener('scroll', this.handleScroll)
  },
  destroyed () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>
<style lang="stylus" scoped>
  @import '~styles/varibles.styl'
  .header
    .header-abs
      position absolute
      top .1rem
      left .1rem
      width .72rem
      height .72rem
      line-height .72rem
      text-align center
      border-radius 50%
      background-color rgba(0,0,0,0.6)
      .header-abs-back
        color #ffffff
        font-size .34rem
        font-weight bold
    .header-fixed
      z-index 2
      position fixed
      top 0
      left 0
      right 0
      overflow hidden
      height $headerHeight
      line-height $headerHeight
      text-align center
      color #ffffff
      background-color $bgColor
      font-size .32rem
      .header-fixed-back
        position absolute
        width .64rem
        text-align center
        top 0
        left 0
        color #ffffff
        font-size .4rem
</style>
